The state of Kerala has been demarcated into three geographical zones after considering the trends in urban growth, land-use pattern, spatial structure and functional morphology.  The three classifications include the following:
(i)             Inner zone
(ii)           Middle zone
(iii)          Outer zone
 
The inner zone always covered the central area of the towns and cities, i.e., the area surrounding the bazaars and the heart of the city, which includes the administrative offices.  It roughly spreads outward from the central bazaar.  Boundaries are drawn only when a major river or a canal passed through it.  This area also covers the most costly portion of the original center of the main business area.  Thus, it is the historic core as well as the core of the modernized city areas of the state.  It is the most intensive commercial area surrounded by a dense residential area. 
 
The road pattern around the central business areas gives a view of ‘grid’ or ‘web’.  Roughly it resembles a egg-type topography.  No area is vacant; hence, further expansion of business areas is not possible in this zone.  More than 90 percent of the zone is fully built up.  It suffers from the haphazard, unplanned growth of the urban area since the pre-independence period except a few readjustments and modifications that were made according to the British colonial administration’s improvement plan for the cities.
 
In Kerala Houses with a traditional charm and ambience that stood side by side with the commercial establishments are now increasingly getting converted into commercial establishments.  It is the lure of easy money that is forcing these residents to move out.  The middle zone and the outer zones are now totally dominated by residential units.  While the middle zone is witnessing a proliferation of high rise apartment complexes, the outer zone is dominated by individual homes.